Generally, the widely-used peripheral input device of a computer system includes for example a mouse device, a keyboard device, a trackball device, or the like. Via the keyboard device, characters or symbols can be inputted into the computer system directly. As a consequence, most users and most manufacturers of input devices pay much attention to the development of keyboard devices.
The structures and the functions of a conventional keyboard device 1 will be illustrated as follows. Please refer to FIGS. 1, 2 and 3. FIG. 1 is a schematic top view illustrating the outer appearance of a conventional keyboard device. FIG. 2 is a schematic exploded view illustrating a portion of the keyboard device of FIG. 1 and taken along a viewpoint. FIG. 3 is a schematic exploded view illustrating a portion of the keyboard device of FIG. 1 and taken along another viewpoint. For succinctness, only one key 10′ and the related components are shown in FIGS. 2 and 3.
The conventional keyboard device 1 comprises plural keys 10 and 10′, a base plate 11 and a membrane circuit board 12. The membrane circuit board 12 comprises plural membrane switches 121 corresponding to the plural keys 10 and 10′. Each of the plural keys 10 and 10′ comprises a keycap 101, at least one scissors-type connecting element 102 and an elastic element 103. The keycap 101 comprises a covering body 1016 and a skirt part 1017. The skirt part 1017 is connected with an edge of the covering body 1016 and protruded downwardly. The scissors-type connecting element 102 is connected between a bottom surface of the covering body 1016 of the keycap 101 and the base plate 11. Moreover, the scissors-type connecting element 102 comprises a first frame 1021 and a second frame 1022. The second frame 1022 is pivotally coupled to the first frame 1021. Consequently, the first frame 1021 and the second frame 1022 can be swung relative to each other. The elastic element 103 is arranged between the keycap 101 and the base plate 11. Moreover, the elastic element 103 comprises a contacting part 1031.
While the keycap 101 of any key 10 or 10′ is depressed and moved downwardly relative to the base plate 11, the first frame 1021 and the second frame 1022 of the scissors-type connecting element 102 are switched from an open-scissors state to a stacked state. Moreover, as the keycap 101 is moved downwardly to compress the elastic element 103, the corresponding membrane switch 121 is pushed and triggered by the contacting part 1031 of the elastic element 103. Consequently, the keyboard device 1 generates a corresponding key signal. When the keycap 101 of the key 10 or 10′ is no longer depressed, the keycap 101 is moved upwardly relative to the base plate 11 in response to an elastic force of the elastic element 103. Meanwhile, the first frame 1021 and the second frame 1022 are switched from the stacked state to the open-scissors state again, and the keycap 101 is returned to its original position.
As shown in the drawings, the length L1 of the key 10′ is much larger than the width W1 of the key 10′. The key 10′ further comprises two stabilizer bars 104. Each first stabilizer bar 104 comprises a main bar part 1041 and two hook parts 1042. The two hook parts 1042 are located at two ends of the main bar part 1041, respectively.
The base plate 11 comprises a first connecting structure 111 and a second connecting structure 112. The first connecting structure 111 and the second connecting structure 112 are protruded upwardly from the base plate 12, and penetrated through the membrane circuit board 12. The first connecting structure 111 comprises two first locking holes 1111. The second connecting structure 112 comprises two second locking holes 1121 corresponding to the two first locking holes 1111. The main bar part 1041 of the each stabilizer bar 104 is pivotally coupled to the keycap 101 of the key 10′. The two hook parts 1042 of each stabilizer bar 104 are penetrated through the corresponding first locking hole 1111 of the first connecting structure 111 and the corresponding second locking hole 1121 of the second connecting structure 112, respectively.
FIG. 4 schematically illustrates the actions of the stabilizer bars of the keyboard device as shown in FIG. 1. While the keycap 101 of the key 10′ is moved upwardly or downwardly relative to the base plate 11, the stabilizer bars 104 are moved in the direction D11 or the direction D12 and rotated in the direction D13 or the direction D14. By this design, the key 10′ is kept stable and not inclined while the key 10′ is moved upwardly or downwardly relative to the base plate 11. Moreover, this design is helpful to increase the strength of the keycap 101.
However, the conventional keyboard device 1 still has some drawbacks. While the keycap 101 of any key 10 or 10′ is depressed and downwardly relative to the base plate 11, the main bar parts 1041 of the stabilizer bars 104 collide with the base plate 11 or the membrane circuit board 12 to generate a sound. Generally, the sound is unpleasant noise to the user. For solving the above drawbacks, a keyboard device with a buffering part has been disclosed.
FIG. 5 is a schematic perspective view illustrating the stabilizer bars, the base plate and the membrane circuit board of a conventional keyboard device with a buffering part. In comparison with the keyboard device 1 of FIG. 4, the keyboard device 1A of FIG. 5 further comprises strip-like elastic vibration absorbers 13. The elastic vibration absorbers 13 are aligned with the whole main bar parts 1041 of the stabilizer bars 104 and disposed on the base plate 11 or the membrane circuit board 12. While the keycap 101 of any key 10 or 10′ is depressed and downwardly relative to the base plate 11, the main bar parts 1041 of the stabilizer bars 104 directly collide with the elastic vibration absorbers 13. Consequently, the sound resulted from the collision between the main bar parts 1041 and the base plate 11 or the membrane circuit board 12 is reduced.
However, the conventional keyboard devices 1 and 1A still have some drawbacks. Please refer to FIGS. 2 and 3 again. For the keyboard device 1 or 1A, the skirt part 1017 of the keycap 101 has a height H. While the keycap 101 of any key 10 or 10′ is depressed and downwardly relative to the base plate 11, the skirt part 1017 of the keycap 101 also collides with the base plate 11 or the membrane circuit board 12 to generate a sound. Generally, the sound is unpleasant noise to the user.
In other words, the conventional keyboard devices 1 and 1A need to be further improved.